The advertising watchdog has given Greenpeace a dressing down for running an "irresponsible" ad campaign to raise funds to takeover and deface property to make environmental protests.

Greenpeace ran a campaign on its website, www.greenpeacegiving.org.uk, calling for donations to support direct action protests against power station chimneys.

The text asked web users to send an £80 gift to fund Greenpeace activists "redecorating" power station chimneys with slogans, such as "stupid" and "no new coal", and was accompanied by a person in a climbing harness occupying a site.

There was one complaint to the Advertising Standards Authority that the campaign was harmful and irresponsible because it encouraged consumers to sponsor illegal activity and encouraged and condoned anti-social behaviour.

Greenpeace said it took non-violent direct action to protect the planet from environmental harm and that it did not aim to break the law.

The group added it took non-violent direct action based on the intention to protect the planet from environmental harm and they did not aim to break the law.

While Greenpeace might not have fallen foul of the law, other similar activity might lead to acts that were illegal or anti-social, the ASA ruled.

"We considered that defacing property would generally be viewed as anti-social, and would in some circumstances be illegal," said the ASA. "We therefore concluded that the ad was harmful and irresponsible because it encouraged and condoned anti-social behaviour."

The ASA told Greenpeace it cannot run the campaign again.

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